Balancing rock

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Sierra de Organos National Park, Mexico SierradeOrganos.jpg
Sierra de Organos National Park, Mexico

A balancing rock, also called a balanced rock, precariously balanced rock (PBR), or precarious boulder, is a naturally occurring geological formation featuring a large rock or boulder, sometimes of substantial size, resting on other rocks, bedrock, or on glacial till. Some formations known by this name only appear to be balancing, but are in fact firmly connected to a base rock by a pedestal or stem.

Contents

No single scientific definition of the term exists, and it has been applied to a variety of rock features.

Categories

Types of feature that the term has been applied to include:

Glacial erratic
A boulder that was transported and deposited by glaciers or ice rafts to a resting place on soil, on bedrock, or on other boulders. It usually has a different lithology from the other rocks around it. Not all glacial erratics are balancing rocks; some are firmly seated on the ground. Some balancing erratics have come to be known as rocking stones, also known as logan rocks, logan stones, or logans, because they are so finely balanced that the application of just a small force may cause them to rock or sway. A good example of a rocking stone is the Logan Rock in Cornwall, England, United Kingdom; another is the Trembling Rock in Brittany, France. [1]
Perched block
Also known as a perched boulder or perched rock, this is a large, detached rock fragment that most commonly was transported and deposited by a glacier to a resting place on glacial till, often on the side of a hill or slope. Some perched blocks were not produced by glacial action, but were the aftermath of a rock fall, landslide, or avalanche. [2]
Erosional remnant
A persisting rock formation that remains after extensive wind, water, and/or chemical erosion. To the untrained eye, it may appear to be visually like a glacial erratic, but instead of being transported and deposited, it was carved from the local bedrock. Many good examples of erosional remnants are seen in Karlu Karlu/Devils Marbles Conservation Reserve in the Northern Territory of Australia.
Pedestal rock
Also known as a rock pedestal or mushroom rock, this is not a true balancing rock, but is a single continuous rock form with a very small base leading up to a much larger crown. Some of these formations are called balancing rocks because of their appearance. The undercut base was attributed for many years to simple wind abrasion, but is now believed to result from a combination of wind and enhanced chemical weathering at the base where moisture would be retained longest. Some pedestal rocks sitting on taller spire formations are known as hoodoos.

Notable balancing rocks

Africa

Mother and Child balancing rocks, Matobo National Park, Zimbabwe Balancing Rocks in Matopos National Park.jpg
Mother and Child balancing rocks, Matobo National Park, Zimbabwe

Zimbabwe

The Balancing Rocks of Epworth on the Zimbabwe $100 trillion note Zimbabwe $100 trillion 2009 Obverse.jpg
The Balancing Rocks of Epworth on the Zimbabwe $100 trillion note
  • The balancing rocks of Zimbabwe are a series of geological formations found in Zimbabwe. The Balancing Rocks of Epworth are famous for being featured on the nation's banknotes, including those issued during periods of hyperinflation, such as the Zimbabwean 100 trillion dollar note, one of the highest denomination banknotes ever issued.
  • The Mother and Child balancing rocks are a well-known feature in Matobo National Park.

Asia and Australia

India

Krishna's Butterball in Mahabalipuram, India Tricky rock.jpg
Krishna's Butterball in Mahabalipuram, India

Australia

Vietnam

Myanmar

Europe

England

Finland

Kummakivi in Haukonsalo, Ruokolahti, Finland Kummakivi balancing rock in Ruokolahti, Finland.jpg
Kummakivi in Haukonsalo, Ruokolahti, Finland

Poland

Chybotek, Giant Mountains, Poland 1304 Chybotek Szklarska Poreba DJE 2.jpg
Chybotek, Giant Mountains, Poland

Spain

  • Pedra de abalar – granite balancing rock in Muxía (Pedra da barca)
  • El Tornillo (The Screw), El Torcal Nature Reserve, Spain
  • Pena do Equilibrio – Giant granite balancing rock resulting from spheroidal weathering, located in Ponteareas (Pontevedra, NW Spain).

Norway

North America

Canada

The Balancing Column near Digby, Long Island, Nova Scotia Balancing Rock, NS.jpg
The Balancing Column near Digby, Long Island, Nova Scotia
A tall basalt stack appears to balance precariously above the water near Digby, Nova Scotia.
Located near Bear Beach on the Juan De Fuca Trail, this solid rock is perched upon eroded sandstone.

United States

Pinnacle Balanced Rock, Chiricahua National Monument, Arizona A089, Chiricahua National Monument, Arizona, USA, 2004.jpg
Pinnacle Balanced Rock, Chiricahua National Monument, Arizona
Several pedestal rocks are found within the boundaries of the Chiricahua National Monument, and two are easily accessible in Marble Canyon, between Navajo Bridge and Lee's Ferry. [10]
A large balancing rock may be easily seen at D.L. Bliss State Park on the west shore of Lake Tahoe.
A huge sandstone boulder hangs precariously near the roadway in Garden of the Gods park near Colorado Springs.
Garden of the Gods, Colorado Springs, Colorado Balanced Rock.jpg
Garden of the Gods, Colorado Springs, Colorado
Balanced Rock is located south of Buhl in Salmon Falls Creek Canyon; created some 15 million years ago and comprising rhyolite lava, it stands 8 feet (2.4 m) tall, weighs 30 tons (27.215 metric tons), and is perched on a 3 foot by 17 inch (0.395 m2) pedestal. [11]
A glacial erratic rests on the edge of a precipice on a mountain in Acadia National Park.
A balanced rock beside the Shore Path in downtown Bar Harbor.
In Balance Rock Park, in Pittsfield State Forest, a field of massive boulders left on a hillside by receding glaciers is crowned by Balance Rock, a tremendous rock balancing almost unbelievably upon a smaller rock protruding from the ground.
A site near Lake Billy Chinook is known as Balancing Rocks or as the Metolius Balancing Rocks. [12] [13]
Several sites around the state, including the Bisti Badlands, Kasha-Katuwe Tent Rocks National Monument, the Ah-Shi-Sle-Pah Wilderness, Chaco Canyon National Park, Red Rock State Park, and in private and BLM public lands throughout New Mexico .
Balanced Rock in North Salem, in Westchester County, New York. A glacial erratic that rests securely on five other rocks pointing upright, the Balanced Rock itself is a heavily weathered pink granite that is not local to the area, and is in fact found further north in the Hudson Highlands.
The Devil's Head is a large boulder perched on the ledge of a cliff in the Chimney Rock State Park, North Carolina.
Balanced Rock, Big Bend National Park, Texas A083, Big Bend National Park, Texas, USA, balanced rock, 2004.jpg
Balanced Rock, Big Bend National Park, Texas
Balanced Rock (also called Window Rock) is a large boulder suspended between two pedestals in the Grapevine Hills of Big Bend National Park.
One of the most visited formations in the United States is the Balanced Rock in Arches National Park.
A large glacial erratic is at the south end of Omak Lake in Okanogan County, known as the Omak Rock.
Located in Devil's Lake State Park. A big rock near the top of a trail with the same name with a view on the lake.

Mexico

At Sierra de Organos National Park in the municipality of Sombrerete there are two balancing rocks near each other.
Sierra de Organos National Park at Mexico SierradeO 05.jpg
Sierra de Organos National Park at Mexico

South America

Argentina

See also

Related Research Articles

<span class="mw-page-title-main">Boulder</span> Natural rock fragment larger than 10 inches

In geology, a boulder is a rock fragment with size greater than 25.6 cm (10.1 in) in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones.

<span class="mw-page-title-main">Karlu Karlu / Devils Marbles Conservation Reserve</span> Protected area in the Northern Territory, Australia

Karlu Karlu / Devils Marbles Conservation Reserve is a protected area in the Northern Territory of Australia located in the locality of Warumungu about 105 km (65 mi) south of Tennant Creek, and 393 km (244 mi) north of Alice Springs. The nearest settlement is the small town of Wauchope located 9 km (5.6 mi) to the south. The hamlet of Wycliffe Well is located 25 km (16 mi) to the south.

<span class="mw-page-title-main">Geology of the Yosemite area</span>

The exposed geology of the Yosemite area includes primarily granitic rocks with some older metamorphic rock. The first rocks were laid down in Precambrian times, when the area around Yosemite National Park was on the edge of a very young North American continent. The sediment that formed the area first settled in the waters of a shallow sea, and compressive forces from a subduction zone in the mid-Paleozoic fused the seabed rocks and sediments, appending them to the continent. Heat generated from the subduction created island arcs of volcanoes that were also thrust into the area of the park. In time, the igneous and sedimentary rocks of the area were later heavily metamorphosed.

<span class="mw-page-title-main">Hoodoo (geology)</span> Tall, thin spire of relatively soft rock usually topped by harder rock

A hoodoo is a tall, thin spire of rock formed by erosion. Hoodoos typically consist of relatively soft rock topped by harder, less easily eroded stone that protects each column from the elements. They generally form within sedimentary rock and volcanic rock formations.

<span class="mw-page-title-main">Grand Coulee</span> Ancient river bed in the U.S. state of Washington

Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about 60 miles (100 km) southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower Grand Coulee.

<span class="mw-page-title-main">Glacial erratic</span> Piece of rock that has been moved by a glacier

A glacial erratic is a glacially deposited rock differing from the type of rock native to the area in which it rests. Erratics, which take their name from the Latin word errare, are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Big Rock in Alberta.

<span class="mw-page-title-main">Geology of the Death Valley area</span> Geology of the area in California and Nevada

The exposed geology of the Death Valley area presents a diverse and complex set of at least 23 formations of sedimentary units, two major gaps in the geologic record called unconformities, and at least one distinct set of related formations geologists call a group. The oldest rocks in the area that now includes Death Valley National Park are extensively metamorphosed by intense heat and pressure and are at least 1700 million years old. These rocks were intruded by a mass of granite 1400 Ma and later uplifted and exposed to nearly 500 million years of erosion.

<span class="mw-page-title-main">Mushroom rock</span> Naturally occurring rock whose shape resembles a mushroom

A mushroom rock, also called rock pedestal, or a pedestal rock, is a naturally occurring rock whose shape, as its name implies, resembles a mushroom. The rocks are deformed in a number of different ways: by erosion and weathering, glacial action, or from a sudden disturbance. Mushroom rocks are related to, but different from, yardang.

<span class="mw-page-title-main">Stawamus Chief</span> Mountain in British Columbia, Canada

The Stawamus Chief, officially Stawamus Chief Mountain, is a granitic dome located adjacent to the town of Squamish, British Columbia, Canada. It towers over 700 m (2,297 ft) above the waters of nearby Howe Sound. It is one of the largest granite monoliths in the world.

<span class="mw-page-title-main">Plucking (glaciation)</span> Glacial erosion of bedrock

Plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the weathering and erosion of pieces of bedrock, especially large "joint blocks". This occurs in a type of glacier called a "valley glacier". As a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock. The freezing and thawing action of the ice enlarges, widens, or causes further cracks in the bedrock as it changes volume across the ice/water phase transition, gradually loosening the rock between the joints. This produces large chunks of rock called joint blocks. Eventually these joint blocks come loose and become trapped in the glacier.

<span class="mw-page-title-main">Rocking stone</span> Large precariously balanced stones

Rocking stones are large stones that are so finely balanced that the application of just a small force causes them to rock. Typically, rocking stones are residual corestones formed initially by spheroidal weathering and have later been exposed by erosion or glacial erratics left by retreating glaciers. Natural rocking stones are found throughout the world. A few rocking stones might be man-made megaliths.

<span class="mw-page-title-main">Tripod Rock</span> Balancing boulder in Kinnelon, New Jersey

Tripod Rock is a glacial erratic, in this specific case a balancing rock, or perched boulder, located in Kinnelon, New Jersey in the Pyramid Mountain Natural Historic Area. This multi-ton Precambrian gneiss boulder, located near the edge of a long ridge, is balanced on three smaller boulders. Tripod Rock is roughly 6 m (20 ft) long, 3 m (9.8 ft) wide, and 2.5 m high, weighing approximately 127 tonnes (280,000 lb). A triangular crest runs the length of its top. The boulder is balanced on three smaller stones roughly 1 m in diameter that raise it above the bedrock by about 0.5 m at its lowest point. The point of contact between the boulder and its support stones forms an approximate 3-4-5 triangle.

<span class="mw-page-title-main">Sims Corner Eskers and Kames</span>

Sims Corner Eskers and Kames National Natural Landmark of Douglas County, Washington and nearby McNeil Canyon Haystack Rocks and Boulder Park natural landmarks contain excellent examples of Pleistocene glacial landforms. Sims Corner Eskers and Kames National Natural Landmark includes classic examples of ice stagnation landforms such as glacial erratics, terminal moraines, eskers, and kames. It is located on the Waterville Plateau of the Columbia Plateau in north central Washington state in the United States.

<span class="mw-page-title-main">The Monoliths (Manchester-by-the-Sea)</span>

The Monoliths, also known as Agassiz Rock, is a 116-acre (47 ha) park in Manchester-by-the-Sea, Massachusetts, owned and maintained by The Trustees of Reservations. The park's name is from two examples of large glacial erratic boulders plucked from bedrock. As glaciers scoured this landscape, the mass of bedrock forming the hill proved more resistant than the surrounding soil, forcing the bottom of the glacier up and over the hill. The north side was smoothed and the south side left steep and rugged as the glacier broke off chunks of rock as it passed.

<span class="mw-page-title-main">Dropstone</span> Rock fragments found within host rock

Dropstones are isolated fragments of rock found within finer-grained water-deposited sedimentary rocks or pyroclastic beds. They range in size from small pebbles to boulders. The critical distinguishing feature is that there is evidence that they were not transported by normal water currents, but rather dropped in vertically through the air or water column, such as during a volcanic eruption.

<span class="mw-page-title-main">Boulder Park</span>

Boulder Park National Natural Landmark, of Douglas County, Washington, along with the nearby McNeil Canyon Haystack Rocks and Sims Corner Eskers and Kames natural landmarks, illustrate well-preserved examples of classic Pleistocene ice stagnation landforms that are found in Washington. These landforms include numerous glacial erratics and haystack rocks that occur near and on the Withrow Moraine, which is the terminal moraine of the Okanogan ice lobe.

<span class="mw-page-title-main">Geology of New England</span> Overview of the geology of New England

New England is a region in the North Eastern United States consisting of the states Rhode Island, Connecticut, Massachusetts, New Hampshire, Vermont, and Maine. Most of New England consists geologically of volcanic island arcs that accreted onto the eastern edge of the Laurentian Craton in prehistoric times. Much of the bedrock found in New England is heavily metamorphosed due to the numerous mountain building events that occurred in the region. These events culminated in the formation of Pangaea; the coastline as it exists today was created by rifting during the Jurassic and Cretaceous periods. The most recent rock layers are glacial conglomerates.

Glacial erratic boulders of Snohomish County are large glacial erratic boulders of rock which were moved to Snohomish County, Washington by glacial action during previous ice ages.

References

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  2. Haddad, David. "Nature's Balanced Seismometers" . Retrieved 18 February 2010.
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  4. "Balancing Rock". Trawell. Retrieved 4 August 2020.
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  8. vi:Hòn Chồng và Hòn Vợ
  9. "Karrta Paikka" (in Finnish). National Land Survey of Finland. Retrieved 1 December 2013.[ permanent dead link ]
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  11. "What to do at Balanced Rock Park". 16 December 2021.
  12. Gentzler, Corbin (20 August 2014). "Go Here: Balancing Rocks". Source Weekly. Retrieved 2 October 2024.
  13. "Nature on an even keel at Oregon's Balancing Rock". 25 May 2023.